The Center for Disease Control (CDC) estimates the yearly incidence of mild Traumatic Brain Injury (mTBI) at approximately 1.2 million cases in the United States alone. Approximately 1/3 of these injuries occur in football. The Principal Objective of this NIH Phase I SBIR project is to develop and validate the sensing and electronics components of HitAlert", a low cost head impact alert system for monitoring mTBI for widespread use. Brain injury is difficult to "see", particularly on the field. What is lacking from the current state-of-the-art clinical techniques is the identification of the impact or series of impacts that triggers the clinical symptoms and changes in brain physiology that are indicative of concussion in the athlete. HitAlert provides the enabling technology that allows users at all playing levels to receive the highest level of care. PUBLIC HEALTH RELEVANCE: The Center for Disease Control (CDC) estimates the yearly incidence of mild Traumatic Brain Injury (mTBI) at approximately 1.2 million cases in the United States alone. Approximately 1/3 of these injuries occur in football. mTBI is a major source of lost player time. Head injuries accounted for 13.3% of all football injuries to boys and 4.4% of all soccer injuries to both boys and girls in a large study of high school sports injuries. Approximately 62,800 mTBI cases occur annually among high school varsity athletes, with football accounting for about 63% of cases. Concussions in hockey affect 10% of the athletes and make up 12%-14% of all injuries. 4-6 concussions occur per year in a football team of 90 players (7%), and 6 per year from a hockey team with 28 players (21%). mTBI has been recognized as a major public health issue and much emphasis has been put on proper treatment and prevention. The NIH and CDC have declared that reducing the incidence, severity, and post-injury symptomology of mTBI is a national research priority. Concussions, particularly when repeated, threaten the long-term health of the athlete. The health care costs associated with mTBI in sports are estimated to be in the hundreds of millions annually.